The Nikon AF-S Zoom-NIKKOR 17-35mm f/2.8D IF-ED is an ultra-wide-angle zoom lens built for candid photography in challenging lighting conditions. Several technologies combine to allow shooting in low lighting conditions, and with a 2.1x zoom the 17-35mm focal length makes this lens ideal for photojournalism and candid photography. The rounded 9 blade diaphragm creates a narrow field of view, creating a natural highlighting effect around the subject. The f/2.8 to f/22 aperture range allows for shooting in a wide variety of lighting conditions, and the internal focusing Silent Wave Motor (SWM) allows for quick and accurate focus on the subject. Extra-low Dispersion (ED) glass elements and Aspherical Elements work to increase optical performance, allowing the capture of sharp images even in low lighting.